rockbox/firmware/timer.c

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/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright (C) 2005 Jens Arnold
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
****************************************************************************/
#include <stdbool.h>
#include "config.h"
#include "cpu.h"
#include "system.h"
#include "timer.h"
#include "logf.h"
static int timer_prio = -1;
void SHAREDBSS_ATTR (*pfn_timer)(void) = NULL; /* timer callback */
void SHAREDBSS_ATTR (*pfn_unregister)(void) = NULL; /* unregister callback */
/* Register a user timer, called every <cycles> TIMER_FREQ cycles */
bool timer_register(int reg_prio, void (*unregister_callback)(void),
long cycles, void (*timer_callback)(void)
IF_COP(, int core))
{
if (reg_prio <= timer_prio || cycles == 0)
return false;
if (!timer_set(cycles, true))
return false;
pfn_timer = timer_callback;
/* NOTE: if unreg cb is defined you are in charge of calling timer_unregister() */
pfn_unregister = unregister_callback;
timer_prio = reg_prio;
return timer_start(IF_COP(core));
}
bool timer_set_period(long cycles)
{
return timer_set(cycles, false);
}
/* NOTE: unregister callbacks are not called by timer_unregister()
* the unregister_callback only gets called when your timer gets
* overwritten by a lower priority timer using timer_register() */
void timer_unregister(void)
{
timer_stop();
pfn_timer = NULL;
pfn_unregister = NULL;
timer_prio = -1;
}